xmlns:util not found

[alicera]

https://www.hass.de/content/wix-how-use-removefolderex-your-xml-scripts

xmlns:util="http://schemas.microsoft.com/wix/UtilExtension">
I set the function and build it .
It show the xmlns:util not found

error CNDL0200 : The Component element contains an unhandled extension element 'util:RemoveFolderEx'. Please ensure that the extension for elements in the 'http://schemas.microsoft.com/wix/UtilExtension' namespace has been provided.

[alicera]

xmlns:util="http://schemas.microsoft.com/wix/UtilExtension">

[wyrdfish]

The article you posted has the answers, are you following all the steps?
You need to tell the compiler to use the extension, with with a reference in visual studio or on the command line.

https://wixtoolset.org/documentation/manual/v3/howtos/general/extension_usage_introduction.html

[alicera]

if I use it , how to include the extension
set(CPACK_WIX_TEMPLATE ${CMAKE_CURRENT_SOURCE_DIR}/cmake/wix.template.in)

https://stackoverflow.com/questions/46362937/wix-utilremovefolderex-does-not-work

[robmen]

You should go ask CPACK.